Hi,Kazu
Would you like to help review this patch?
qianli zhao <zhaoqianligood@xxxxxxxxx> 于2022年6月24日周五 10:56写道：
>
> Hi,all
>
> Here's some explanation for this patch
>
> Without patch:
> Consider the following scenario
> ->arm64_init(PRE_GDB)
> case PRE_GDB:
> ...
> 292 } else if (ms->VA_BITS_ACTUAL) {
> 293 ms->modules_vaddr =
> (st->_stext_vmlinux & TEXT_OFFSET_MASK) -
> ARM64_MODULES_VSIZE;-->//ms->modules_vaddr=0xfffffffff8000000
> 294 ms->modules_end =
> ms->modules_vaddr + ARM64_MODULES_VSIZE
> -1;--->//ms->modules_end=0xffffffffffffffff
> 295 ms->vmalloc_start_addr =
> ms->modules_end + 1;--->//ms->vmalloc_start_addr=0
> 296 } else {
> ....
> }
> arm64_calc_kimage_voffset();
> .....
>
> Since arm64_calc_kimage_voffset() depends on vmalloc_start_addr,
> kimage_voffset cannot be calculated correctly.
>
> st->_stext_vmlinux can be initialized in numeric_forward(),just set
> st->_stext_vmlinux to UNINITIALIZED.
>
> ============
> log as below:
>
> $ ~/crash/crash/crash vmlinux DDRCS0.bin@0x80000000 --machdep vabits_actual=48
>
> crash 8.0.1++
> Copyright (C) 2002-2022 Red Hat, Inc.
> Copyright (C) 2004, 2005, 2006, 2010 IBM Corporation
> Copyright (C) 1999-2006 Hewlett-Packard Co
> Copyright (C) 2005, 2006, 2011, 2012 Fujitsu Limited
> Copyright (C) 2006, 2007 VA Linux Systems Japan K.K.
> Copyright (C) 2005, 2011, 2020-2022 NEC Corporation
> Copyright (C) 1999, 2002, 2007 Silicon Graphics, Inc.
> Copyright (C) 1999, 2000, 2001, 2002 Mission Critical Linux, Inc.
> Copyright (C) 2015, 2021 VMware, Inc.
> This program is free software, covered by the GNU General Public License,
> and you are welcome to change it and/or distribute copies of it under
> certain conditions. Enter "help copying" to see the conditions.
> This program has absolutely no warranty. Enter "help warranty" for details.
>
> NOTE: setting vabits_actual to: 48
>
> WARNING: kimage_voffset cannot be determined from the dumpfile.
> Try using the command line option: --machdep kimage_voffset=<addr>
> GNU gdb (GDB) 10.2
> Copyright (C) 2021 Free Software Foundation, Inc.
> License GPLv3+: GNU GPL version 3 or later <http://gnu.org/licenses/gpl.html>
> This is free software: you are free to change and redistribute it.
> There is NO WARRANTY, to the extent permitted by law.
> Type "show copying" and "show warranty" for details.
> This GDB was configured as "--host=x86_64-pc-linux-gnu
> --target=aarch64-elf-linux".
> Type "show configuration" for configuration details.
> Find the GDB manual and other documentation resources online at:
> <http://www.gnu.org/software/gdb/documentation/>.
>
> For help, type "help".
> Type "apropos word" to search for commands related to "word"...
>
> crash: read error: kernel virtual address: ffff80001083d4a0 type:
> "kernel_config_data"
> WARNING: cannot read kernel_config_data
> crash: read error: kernel virtual address: ffff80001170e798 type: "possible"
> WARNING: cannot read cpu_possible_map
> crash: read error: kernel virtual address: ffff80001170e7a8 type: "present"
> WARNING: cannot read cpu_present_map
> crash: read error: kernel virtual address: ffff80001170e788 type: "online"
> WARNING: cannot read cpu_online_map
> crash: read error: kernel virtual address: ffff80001170e7c0 type: "active"
> WARNING: cannot read cpu_active_map
> crash: read error: kernel virtual address: ffff8000122e00f0 type:
> "shadow_timekeeper xtime_sec"
> crash: read error: kernel virtual address: ffff80001171dc04 type: "init_uts_ns"
> crash: vmlinux and /var/tmp/ramdump_elf_m2ivkg do not match!
>
> Usage:
>
> crash [OPTION]... NAMELIST MEMORY-IMAGE[@ADDRESS] (dumpfile form)
> crash [OPTION]... [NAMELIST] (live system form)
>
> Enter "crash -h" for details.
>
> Qianli Zhao <zhaoqianligood@xxxxxxxxx> 于2022年6月24日周五 00:14写道：
> >
> > From: Qianli Zhao <qianli.zhao@xxxxxxxxxx>
> >
> > Setting st->_stext_vmlinux to UNINITIALIZED to search for "_stext" from the vmlinux
> > Without the patch, if we do not enable kaslr, will get the wrong
> > MODULES/VMALLOC ranges, cause parsing dump failure
> >
> > Signed-off-by: Qianli Zhao <qianli.zhao@xxxxxxxxxx>
> > ---
> > arm64.c | 3 +++
> > 1 file changed, 3 insertions(+)
> >
> > diff --git a/arm64.c b/arm64.c
> > index 0f615cf..4458a66 100644
> > --- a/arm64.c
> > +++ b/arm64.c
> > @@ -149,6 +149,9 @@ arm64_init(int when)
> >
> > ms = machdep->machspec;
> >
> > + if (ms->VA_BITS_ACTUAL)
> > + st->_stext_vmlinux = UNINITIALIZED;
> > +
> > if (!ms->kimage_voffset && STREQ(pc->live_memsrc, "/dev/crash"))
> > ioctl(pc->mfd, DEV_CRASH_ARCH_DATA, &ms->kimage_voffset);
> >
> > --
> > 2.17.1
> >
--
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